1. Field of the Invention
The present invention relates to a front lighting unit and a liquid crystal display (LCD) using such a front lighting unit.
2. Description of the Related Art
Liquid crystal displays (LCDs) have been used in various kinds of devices including portable wireless communication units such as handheld wireless telephone sets.
FIG. 6 is a schematic longitudinal section of a portion of a handheld telephone showing a conventional LCD. In FIG. 6, the telephone has a casing including a front portion 601 and a back portion 602. By metal plating, a thin layer of metal 603 is formed on the front portion 601. A protective member in the form of a protective cover 604 is placed to cover an opening or window 605 of the front portion 601. Disposed between the front portion 601 and a back portion 602 is a translucent LCD panel 606 with a backlighting unit 607. The LCD panel 606 is formed over the backlighting unit 607.
To meet a request for portable wireless communication units to install color LCDs, it is recommendable to use a reflective color LCD, which is of low energy consumption. Reflective color LCD is needed especially in handheld telephones, which may be used in dark places. Reflective color LCD requires a front lighting unit. Examples of a LCD using a front lighting unit are described in JP-A 10-161123, JP-A 11-218757, JP-A 11-232919, JP-A 11-326903, and JP-A 11-344695.
In FIG. 6, a substrate of the LCD panel 606 uses glass. To prevent the substrate from breaking, there is a need for provision of sufficient amount of distance between the protective cover 604 and the LCD panel 606. It is also needed to use a protective cover with a sufficient amount of thickness around 1 mm for required strength. These make a further reduction in thickness difficult.
JP-A 11-344695 discloses a LCD employing a laminated structure of a transparent touch panel placed on a light conductive panel of a front lighting unit. Employing this structure, there is a reduction in thickness to some degree. The touch panel does not serve as a protective member.
An object of the present invention is to provide a front lighting unit that may make much contribution to a reduction in thickness of a liquid crystal display.
Another object of the present invention is to provide a liquid crystal display employing the front lighting unit.
According to one exemplary implementation of the invention, there is provided a front lighting unit comprising:
a light conductive member having one side; and
a protective member fixedly attached to the one side of the light conductive member to define therebetween a closed space to seal between the light conductive member and the protective member.
According to another exemplary implementation of the invention, there is provided a liquid crystal display comprising:
a front lighting unit including a light conductive member having one side, and a protective member fixedly attached to the one side of the light conductive member to define therebetween a closed space to seal between the light conductive member and the protective member; and
a liquid crystal panel having one side,
the light conductive member of the front lighting unit being fixedly attached to the one side of the liquid crystal panel to define therebetween a closed space to seal between the light conductive member and the liquid crystal panel.